N-K Necrosis was an extremely sophisticated battle droid engineered during the era of the Galactic Civil War. It was constructed using the remains of the deceased General Grievous, a prominent figure from the Confederacy of Independent Systems. The Galactic Empire commissioned Doctor Nycolai Kinesworthy, a cybernetics expert, to bring the Necrosis droid into existence. Kinesworthy, who called the project "N-K," set up a laboratory within the Myyydril Caverns located on the planet Kashyyyk to commence his work. Later, he enlisted the help of fellow scientist Treun Lorn to expedite the project's progress. Lorn then engaged the services of the assassin droid IG-72 with the task of acquiring a couple of obsolete IG-100 MagnaGuards to act as bodyguards for N-K. Subsequently, Merili, a Prophetess of the dark side, guided the two scientists to a concealed storage facility belonging to Emperor Palpatine on Utapau, where they were given the mechanical shell of the cyborg Grievous.
Once an advanced droid brain was integrated into the mechanical form, Kinesworthy christened the final creation "N-K Necrosis" and gave the aging MagnaGuards a new designation: "NK-3." The NK-3 units then proceeded to train Necrosis in lightsaber combat, teaching him how to fight. Necrosis wielded a double-bladed lightsaber powered by the Bane's Heart crystal. Sometime around the period of the Battle of Yavin, Lorn absconded with Necrosis and his NK-3 protectors, intending to use them for his personal schemes. Around 1.5 ABY, a band of spacers explored the lower reaches of the Myyydril Caverns at Kinesworthy's urging. During their exploration, the group inadvertently assisted Lorn in activating Necrosis. They then engaged and defeated N-K Necrosis and his bodyguards, seizing anything they considered valuable before departing.
During the Galactic Civil War, the Galactic Empire hired Doctor Nycolai Kinesworthy, a respected cybernetic [scientist](/article/scientist-legends], to develop a state-of-the-art battle droid. Kinesworthy's study of death and its aspects aided him in designing a groundbreaking droid brain. After completing this, the doctor named his endeavor "N-K," alluding to his own identity. Kinesworthy brought on board a renowned scientist named Treun Lorn, who was instrumental in advancing the project beyond its conceptual phase. Subsequently, both scientists relocated the project to Kashyyyk, the homeworld of the Wookiee species. There, the project was presented to Merili, a Prophetess of the dark side and the Imperial overseer of the planet, who granted Kinesworthy permission to base the project within the Myyydril Caverns on Kashyyyk.
After Lorn contracted the assassin droid IG-72 to gather a pair of antiquated IG-100 MagnaGuards to serve as bodyguards for the advanced battle droid, Merili escorted Kinesworthy and Lorn to Utapau. At one of Emperor Palpatine's clandestine storage facilities there, she presented the two scientists with the droid body of Grievous, the deceased Confederate cyborg general who had perished at the conclusion of the Clone Wars. The droid body was subsequently equipped with Kinesworthy's experimental droid brain and revived as the advanced combat droid, N-K Necrosis. The two MagnaGuards—renamed "NK-3"—instructed the reanimated Grievous in the art of lightsaber fight, employing the same fighting techniques that Grievous had imparted to the MagnaGuards almost two decades prior. Necrosis carried an assortment of weapons, along with the title to Grievous's starfighter, the modified Belbullab-22 starfighter known as the Soulless One.
Necrosis selected a double-bladed lightsaber containing the Bane's Heart crystal, a relic that had once belonged to the Sith Lord Darth Zannah, as his primary weapon. He also received the weapon that had been used to destroy Grievous: a modified BlasTech blaster dubbed the "Grievance Striker." The droid also carried a Utapaun Nightblade.
Around the time of the Battle of Yavin in 0 BBY, Lorn abducted Necrosis and his bodyguards for his personal gain and concealed them deep within the Myyydril Caverns. However, in 1.5 ABY, a group of spacers explored the depths of the Myyydril Caverns during the height of the Galactic Civil War, acting on Kinesworthy's request. During their investigation, the spacers discovered the cave where Necrosis had been hidden, guarded by a vigilant B1-Series battle droid. The droid tasked the spacers with finding a special crystal that could revive Necrosis. After the spacers located the crystal in another part of the caverns, the battle droid granted them access to the cave where Necrosis was held. Inside, the spacers encountered Lorn, who demanded that they surrender the crystal. After the spacers complied, Necrosis and his two NK-3 bodyguards emerged and engaged the group in a fierce battle. The spacers prevailed, destroying both Necrosis and his NK-3 guards. They then plundered the destroyed droid bodies, taking anything of value, including Bane's Heart, other weapons, the deed to the Soulless One, and components of Necrosis's droid body.
The looted parts of Necrosis's droid body, regarded as valuable components, were sold on the Invisible Market. It is said that Necrosis's duraplast armor mask was acquired by a high-ranking Imperial admiral, rumored to be Grand Admiral Thrawn, as a Kaleesh work of art.
Due to the advanced heuristic programming in Kinesworthy's new droid brain, N-K Necrosis exhibited traits reminiscent of the former occupant of his body, the late General Grievous, although Kinesworthy assured Necrosis that he was superior. In addition to the considerable fighting skills acquired through training with the NK-3s, Necrosis also developed an almost Human inclination for analysis, often questioning whether he was truly superior to Grievous or merely an imitation. Necrosis found himself contemplating Grievous's past, experiencing a sense of envy toward the living intelligence that had once inhabited the body. While serving under Lorn, Necrosis addressed him as "master."
N-K Necrosis was highly skilled in melee combat and employed the same lightsaber techniques that Grievous had once taught his MagnaGuard bodyguards during the Clone Wars. Unlike other lightsaber crystals, Necrosis's, the Bane's Heart crystal, underwent alchemically treatment, enhancing the weapon's overall power. Both Necrosis and his NK-3 guards favored close-quarters combat over ranged attacks. With his stronger armor, Necrosis was more powerful than his NK-3 droids. Necrosis's droid body, constructed from duranium alloy, resembled a Krath war droid. While the entire body was cybernetic, a notable feature was the inclusion of LX-44 legs.
N-K Necrosis made his debut in the MMORPG online game Star Wars Galaxies. In April 2005, a month before the theatrical release of Star Wars: Episode III Revenge of the Sith—in which Grievous is featured—Sony Online Entertainment, the developer of Star Wars Galaxies, launched the game's second expansion, titled Rage of the Wookiees. This expansion introduced the planet Kashyyyk into the game, along with the non-player character N-K Necrosis. Upon defeating the NPC, N-K Necrosis typically dropped a deed to Grievous's starfighter, a cybernetic arm, and a somewhat rare weapon. Occasionally, the weapon would be replaced with another cybernetic arm. More infrequently, N-K Necrosis would drop the Bane's Heart lightsaber crystal.
Author Abel G. Peña referenced the character N-K Necrosis in two stories about Grievous's life: Unknown Soldier: The Story of General Grievous from Star Wars Insider 86, and The Story of General Grievous: Lord of War, a StarWars.com Hyperspace online addition. Necrosis also has an entry in The Complete Star Wars Encyclopedia.